The chance of a Brexit deal is getting smaller, European Commission President Ursula von der Leyen said on Wednesday in her first major policy speech, the State of the Union.
She also addressed Boris Johnson's controversial bill, which undermines parts of the Brexit withdrawal agreement.
Von der Leyen warned the British in her speech that there is "very little time" to make a deal before the end of the year.
"Every day the chance of a timely agreement is getting smaller," she said.
She also stressed that the Brexit Withdrawal Agreement "cannot be unilaterally changed or ignored".
She is referring to a bill by British Prime Minister Johnson, which was presented last week.
The proposal explains how the British intend to trade within the UK after Brexit.
Also, if passed, it would give London the power to reject parts of the so-called Northern Ireland Protocol.
This protocol was drawn up last year by the EU and the UK to avoid a hard border on the Irish island.
At the time, Johnson called the deal "very good" and "oven-ready".
With the bill, Johnson returns to those words.